Waste water treatment units

Treatment of steam generator washing water for the nuclear industry

Our Client is a global group present in nearly 19 countries. Founded in the United States, this pioneering company in nuclear energy is a major supplier of technological products and services for nuclear power plants worldwide. Currently, our Client has designed nearly half of the nuclear power plants in operation around the world.

A physico-chemical process for water recycling

The Client company has engaged our services to recycle its wastewater for reuse as washing water. Their industrial maintenance activity, involving the washing of steam generators, generates 10 to 20 cubic meters of wastewater daily. Currently, this water does not meet the discharge standards in effect as it contains, among other things, metal particles, mineral, and lime deposits. This makes our Client to store its wastewater for disposal by an external service provider. They wish to be able to discharge their water into the sewer system while complying with current standards.

A specific and adapted flocculant for heavy metals concentration reduction

Coagulation of metal particles and other pollutant present in steam generator washing water
Coagulation of metal particles and other pollutant present in steam generator washing water

To create a custom flocculant according to our Client’s needs, a representative sample of water from their cleaning operations was analyzed and tested by our laboratory experts. Initially, the water generated by their industrial maintenance activity is of a large daily volume, with a high presence of heavy metals (Copper, Iron, Nickel, and Zinc), a low pH value of 2.87, and a dryness percentage of less than 30%. Dryness, representing the percentage of dry matter, above 30% allows for the reduction of sludge volume to be transported.

Following various tests, a coagulant-flocculant complex adapted to our Client’s application was developed. A dosage of only 2.0 g/L is necessary for treating this water, which is heavily loaded with heavy metals. This custom flocculant application significantly reduces the iron concentration from 20.40 mg/L to a final concentration of 0.16 mg/L, and similarly for copper, from 9.28 mg/L to 0.26 mg/L. The pH is finally neutralized to 7.72. Visually, the solution, initially reddish-brown, has become clear and translucent with sludge accumulating on the surface. The quality of the resulting sludge allows for easy filtration and dehydration.

A solution enabling compliant discharge of washing water

Following the analysis conducted by our experts, NISKAE was able to propose a solution tailored to our Client’s needs. The company is now capable of autonomously recycling its wash water, representing a real-time savings and a reduction in wastewater management costs. Thus, our Client has the appropriate solution to optimize their washing process in line with current sustainable development challenges.